Drill rod welded with wear-resistant structure and welding method

Abstract

The invention provides a drill rod welded with a wear-resisting structure and a welding method, a drill rod body is provided with the wear-resisting structure, the wear-resisting structure comprises a wear-resisting belt, and the wear-resisting belt is in a circular ring shape or a spiral shape; the wear-resistant belt comprises welding beads, each welding bead is in a circular ring shape or a spiral shape, when the welding beads comprise a plurality of welding beads, the welding beads are arranged adjacently, and the welding beads are formed at the same time through a laser cladding process; each wear-resistant belt comprises a base layer structure and a surface layer structure; the bottom layer structures are connected with the outer surface of the drill rod body, and the surface layer structures are connected with the corresponding bottom layer structures; the base layer structure comprises a base layer which is arranged on the outer surface; the surface layer structure comprises a surface layer, the surface layer is arranged on the base layer structure, and the width of the surface layer is reduced in the direction away from the outer surface. The bonding force between the bottom layer and the drill rod body is effectively enhanced, stable attachment of a wear-resistant system is ensured, the surface layer structure is arranged layer by layer, the width is gradually reduced, large-area wear-resistant covering is ensured, and stress distribution is optimized.

Description

Technical Field

[0001] The invention relates to the field of drill rods, in particular to a drill rod with a welded wear-resistant structure and a welding method. Background Art

[0002] As the main tool for drilling, the performance and quality of drill pipe play a key role in drilling capacity, drilling efficiency and quality, and drilling safety, meeting the needs of modern drilling for more efficient drilling (faster drilling speed, higher drilling quality, more suitable for special drilling environments, and safer drilling).

[0003] In drilling projects, drill pipes, as key components, need to frequently withstand complex working conditions such as rock wear, formation friction, and drilling fluid flushing during drilling. Traditional drill pipes are often not wear-resistant enough. After a period of use, their bodies are prone to severe wear, resulting in reduced strength and shortened service life. Frequent replacement of drill pipes not only increases operating costs, but also affects project progress. Summary of the invention

[0004] The object of the present invention is to provide a drill pipe with a welded wear-resistant structure and a welding method, which can effectively reduce the wear of the drill pipe during the drilling process and extend the service life of the drill pipe.

[0005] The embodiment of the present invention is achieved as follows: In a first aspect, the present application provides a drill pipe with a welded wear-resistant structure, comprising a drill pipe body, a wear-resistant structure is arranged in a designated middle area of ​​the drill pipe body, the wear-resistant structure comprises at least one wear-resistant belt, the wear-resistant belt is sequentially arranged around the outer surface of the drill pipe body along the axial direction of the drill pipe body, each of the wear-resistant belts is in a circular ring shape or a spiral shape; each of the wear-resistant belts comprises a group of weld beads, each weld bead in each group of weld beads is in a circular ring shape or a spiral shape, when the group of weld beads comprises a plurality of weld beads, the plurality of weld beads are arranged adjacent to each other, and the plurality of groups of weld beads are welded and formed simultaneously by a laser cladding process; Each wear-resistant belt includes a base layer structure and a surface layer structure; the base layer structure is connected to the outer surface of the drill pipe body, and the surface layer structure is connected to the corresponding base layer structure; the base layer structure includes at least one base layer, and at least one base layer is arranged on the outer surface in a layered manner away from the outer surface; the surface layer structure includes at least one surface layer, and at least one surface layer is arranged on the base layer structure in a layered manner away from the outer surface, and the width of the surface layer gradually decreases in a direction away from the outer surface; each of the base layer and the surface layer are respectively formed by welding through a laser cladding process.

[0006] In a possible implementation manner, the wear-resistant structure includes a plurality of wear-resistant belts, and each of the wear-resistant belts is in a circular ring shape, and the plurality of wear-resistant belts are arranged at a first preset spacing; the maximum value of the first preset spacing is determined according to the dogleg degree of the drill pipe during drilling and the weld thickness of the wear-resistant belt, and the first preset spacing is selected from the maximum value: ; in, It represents the maximum value of the first preset spacing of multiple wear-resistant belts; R represents the curvature radius corresponding to the dog-leg degree; t represents the weld thickness of the wear-resistant belt, and the weld thickness of the multiple wear-resistant belts is the same.

[0007] In a possible implementation, the wear-resistant structure includes a plurality of wear-resistant belts, and each of the wear-resistant belts is spiral; each of the wear-resistant belts is arranged with an equal pitch and the pitch of the plurality of wear-resistant belts is the same, and the pitch is determined by the direction of the tensile stress and the dogleg degree of the drill pipe during drilling; the plurality of wear-resistant belts are spaced apart by a second preset spacing; and the second preset spacing is determined according to the dogleg degree of the drill pipe during drilling: ; in, represents the maximum value of the second preset spacing between multiple wear-resistant belts; R represents the curvature radius corresponding to the dog-leg degree; t represents the weld thickness of the wear-resistant belt, and the thickness of the multiple wear-resistant belts is the same.

[0008] In a possible implementation manner, the thickness range and width range of the wear-resistant belt are determined by: Determine the overall strength and overall wear resistance of the drill pipe with a welded wear-resistant belt according to the drill pipe's own strength, its own wear resistance and the force information of the drill pipe during drilling; the overall strength is not less than the drill pipe's own strength and the overall wear resistance is greater than the own wear resistance; Taking the overall strength and overall wear resistance as constraint conditions, the thickness range and width range of the wear-resistant belt are determined in combination with the material and welding process of the wear-resistant belt.

[0009] In a possible embodiment, each weld bead in a group of weld bead included in each hard-wearing belt has the same thickness; the target thickness and target width of the weld bead are determined by the following method: Determine the number of layers of the wear-resistant belt and the thickness of each layer according to the thickness range of the weld, the heat input of the welding tool and the welding process, determine the first number of layers of each base layer, the first thickness of each layer, and the second number of layers of each surface layer and the second thickness of each surface layer by laser cladding process, and determine the target thickness of the weld according to the first number of layers, the first thickness, the second number of layers and the second thickness; The target width of each layer of the wear-resistant belt is determined according to the width range of the weld bead, the type of welding tool spot and the welding process.

[0010] In a possible implementation manner, the thickness of the wear-resistant belt ranges from 4.0 mm to 6.0 mm, and the width of the wear-resistant belt ranges from 19 mm to 30 mm.

[0011] In a possible implementation manner, the wear-resistant structure corresponds to a wear factor, and the wear factor is determined according to the application object of the drill pipe and the user's demand for the application object; correspondingly, the wear factor of the wear-resistant structure is calculated through one or more wear-resistant belts included therein; Among them, the wear factor includes a reference wear factor and a differential wear factor; the reference wear factor is calculated based on the contact pressure of the drill pipe when drilling under specified conditions in a simulation scenario; the differential wear factor is calculated based on the contact pressure of the drill pipe when drilling when the wear-resistant structure changes at least one parameter in the specified conditions in the simulation scenario; the contact pressure is obtained by measuring the drill pipe in the target area in the simulation scenario; different time periods and / or different target areas correspond to different contact pressures.

[0012] In a possible implementation manner, the length range of the designated middle region has a positive correlation with the deflection of the drill pipe body during operation, and the number of the wear-resistant bands has a positive correlation with the length of the designated middle region.

[0013] In a possible implementation manner, the overall length of the designated middle region ranges from 2m to 3m, and the number of the wear-resistant belts is an even number and they are symmetrically arranged in the designated middle region of the drill pipe body.

[0014] In a possible implementation manner, the outer surface of the drill pipe body is a circumferential surface, and when each of the wear-resistant belts is in a spiral shape, the wear-resistant belt surrounds at least one circumference of the outer surface of the drill pipe body.

[0015] In a possible implementation manner, the base layer structure and the surface layer structure are formed by welding through a laser cladding process, including: Determining welding materials, welding methods and welding parameters of welding tools for the base layer structure and the surface layer structure respectively; Determine a welding path of the welding tool according to the preset shape of each of the wear-resistant belts, and control the welding tool to weld in sequence along the welding path to successively form the base layer and the surface layer; The base layer formed by welding has at least one layer and surrounds at least one circumference of the outer surface, the surface layer formed by welding has at least one layer and surrounds at least one circumference of the outer surface, and the width of the surface layer decreases in the direction away from the outer surface.

[0016] In a possible implementation manner, the welding parameters are determined in the following manner, including: The welding parameters are determined according to the thickness and heat input of the wear-resistant belt, and the welding parameters include welding power, line speed and powder feeding amount; the welding power includes base layer power and surface layer power, wherein the base layer power is a pre-adjusted power matching each base layer, and the surface layer power is adjusted based on the base layer power, and the adjustment includes increasing or decreasing the base layer power within a set range, and the set range is less than 1kw; the line speed is 15~30mm / s, and the powder feeding amount is 1.5~2.5g / s.

[0017] In a possible implementation manner, the base layer power is greater than or equal to 2.0 KW.

[0018] In a possible implementation manner, the number of layers of the base layer is at least one, and the thickness of each layer of the base layer is 0.8mm~1.2mm; the number of layers of the surface layer is multiple; the surface temperature of the wear-resistant belt monomer formed by welding does not exceed 200°C; and the melting depth of the outer surface does not exceed 2mm.

[0019] In a possible implementation manner, the wear-resistant structure base layer corresponds to a Rockwell hardness, and the Rockwell hardness is correlated with the wear factor of the wear-resistant structure; Among them, the correlation is determined in the following manner: according to the application scenario and application object of the drill pipe, the correlation between the Rockwell hardness and the wear factor of the wear-resistant structure in the wear-resistant belt is determined; the correlation includes multiple combinations of multiple preset Rockwell hardness ranges and multiple preset wear factor ranges, and the number of combinations is equal to the product of the number of preset Rockwell hardness ranges and the number of preset wear factor ranges.

[0020] In a possible implementation manner, the Rockwell hardness of the wear-resistant belt is 40HRC-60HRC.

[0021] In a possible implementation manner, the welding spot of the welding tool is a rectangular spot or a circular spot.

[0022] In a second aspect, the present application also provides a method for welding a wear-resistant structure in a drill pipe, comprising: Determining a first structural parameter of a wear-resistant structure in a drill pipe and a second structural parameter of a single wear-resistant belt in the wear-resistant structure; Determining a target welding tool and a target welding method for the wear-resistant structure in the drill pipe according to the first structural parameter and the second structural parameter; Determine welding process parameters according to the first structural parameter, the second structural parameter and the multi-dimensional parameter information of the drill rod; wherein the multi-dimensional parameter information includes: material information, structural information and welding performance; The target welding tool is controlled to use the target welding method and weld the wear-resistant belt according to the welding process parameters to obtain a wear-resistant structure in the drill pipe.

[0023] In a possible implementation manner, when the wear-resistant structure includes a plurality of wear-resistant belts and each of the wear-resistant belts is in a circular ring shape, the first structural parameter includes a first preset spacing, and the plurality of wear-resistant belts are arranged at the same first preset spacing; the second structural parameter includes a weld thickness, and the weld thicknesses of the plurality of wear-resistant belts are the same; Wherein, determining the first preset spacing and the weld thickness includes: Determine the overall strength and overall wear resistance of the drill pipe with a welded wear-resistant belt according to the drill pipe's own strength, its own wear resistance and the force information of the drill pipe during drilling; the overall strength is not less than the drill pipe's own strength and the overall wear resistance is greater than the own wear resistance; Taking the overall strength and overall wear resistance as constraints, determining the thickness range of the wear-resistant belt in combination with the material and welding process of the wear-resistant belt, and determining the weld thickness of the wear-resistant belt from the thickness range; The maximum value of the first preset spacing is determined according to the dogleg degree of the drill pipe during drilling and the weld thickness of the wear-resistant belt, and the first preset spacing is selected from the maximum value: ; in, represents the maximum value of the first preset spacing of multiple wear-resistant belts; R represents the curvature radius corresponding to the dog-leg degree; t represents the weld thickness of the wear-resistant belt.

[0024] In a possible implementation, when the wear-resistant structure includes a plurality of wear-resistant belts and each of the wear-resistant belts is spiral, the first structural parameter includes a second preset spacing, and the plurality of wear-resistant belts are spaced apart by the second preset spacing; the second structural parameter includes a weld thickness, and the weld thicknesses of the plurality of wear-resistant belts are the same; determining the second preset spacing and the weld thickness includes: Determine the overall strength and overall wear resistance of the drill pipe with a welded wear-resistant belt according to the drill pipe's own strength, its own wear resistance and the force information of the drill pipe during drilling; the overall strength is not less than the drill pipe's own strength and the overall wear resistance is greater than the own wear resistance; Taking the overall strength and overall wear resistance as constraints, determining the thickness range of the wear-resistant belt in combination with the material and welding process of the wear-resistant belt, and determining the weld thickness of the wear-resistant belt from the thickness range; The maximum value of the first preset spacing is determined according to the dogleg degree of the drill pipe during drilling and the weld thickness of the wear-resistant belt, and the second preset spacing is selected from the maximum value: ; in, represents the maximum value of the second preset spacing between multiple wear-resistant belts; R represents the curvature radius corresponding to the dog-leg degree; t represents the weld thickness of the wear-resistant belt, and the thickness of the multiple wear-resistant belts is the same.

[0025] In a possible implementation manner, the second structural parameter further includes a pitch, and each of the wear-resistant belts is provided with an equal pitch; and determining the second structural parameter of a single wear-resistant belt in the wear-resistant structure further includes: The pitch is determined by the direction of the tensile stress borne by the drill pipe during the drilling process and the dog-leg degree.

[0026] In a possible implementation manner, the second structural parameter further includes the width of the wear-resistant belt; and the determining the second structural parameter of a single wear-resistant belt in the wear-resistant structure further includes: Determine the overall strength and overall wear resistance of the welded wear-resistant belt drill pipe according to the inherent strength of the drill pipe and the force information of the drill pipe during the drilling process; The overall strength and overall wear resistance are used as constraint conditions, and the width range of the wear-resistant belt is determined in combination with the material and welding process of the wear-resistant belt.

[0027] The beneficial effects of the embodiments of the present invention are as follows: during use, the drill rod of the present application not only has excellent wear resistance, but also has a firm structure and can adapt to different working environments and working conditions, thereby improving the service life and working efficiency of the drill rod and reducing the maintenance and replacement costs caused by drill rod wear.

[0028] The wear-resistant belt has both a base layer structure and a surface layer structure. The base layer is stacked layer by layer in the direction away from the outer surface of the drill pipe body, which effectively enhances the bonding force with the drill pipe body and ensures the stable adhesion of the wear-resistant system to prevent it from falling off and peeling off under complex working conditions. The surface layer structure is also arranged layer by layer with a gradually decreasing width, which not only ensures a large area of ​​wear-resistant coverage, but also optimizes the stress distribution, making the overall force of the wear-resistant belt more uniform, and can efficiently disperse external forces when dealing with friction impact, greatly extending the wear-resistant life of the drill pipe.

[0029] In addition, each wear-resistant belt contains a set of welds, which can be circular or spiral. Multiple welds are arranged adjacently and formed synchronously by laser cladding. The annular welds are tightly surrounded to provide all-round protection and resist friction from different angles; the spiral welds have both continuous protection and adaptability to the circumferential and axial forces of the drill pipe. The collaborative operation makes the wear-resistant belt complete and coherent, without welding weak points, and significantly improves wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 It is a structural schematic diagram of one embodiment of a drill rod with a welded wear-resistant structure according to the present invention; Figure 2 for Figure 1 Sectional view along AA direction; Figure 3 for Figure 2 The enlarged view of point B in the middle; Figure 4 It is a structural schematic diagram of one embodiment of a drill rod with a welded wear-resistant structure according to the present invention; Figure 5 for Figure 4 The enlarged schematic diagram of point D in the middle; Figure 6 for Figure 4 Cross-section along the mid-CC direction; Figure 7 for Figure 6 Enlarged view of point E in the middle; Figure 8 It is a structural schematic diagram of one embodiment of a drill rod with a welded wear-resistant structure according to the present invention; Fig. 9 for Figure 8 Enlarged view of point F in the middle.

[0032] Icons: 1. Drill pipe body; 2. Wear-resistant belt; 21. Weld. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0036] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0037] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0038] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Please refer to Figures 1 to 9 , Figure 1The wear-resistant belt shown is annular and two are symmetrically arranged. Figure 2 for Figure 1 The cross-sectional view along the AA direction, Figure 3 for Figure 2 The enlarged view at B shows 9 welds. Figure 4 The wear-resistant belt shown is spiral and arranged in the middle of the drill pipe body. Figure 5 for Figure 4 The enlarged schematic diagram of point D in the middle, Figure 6 for Figure 4 Cross-sectional view along CC direction, Figure 7 for Figure 6 The enlarged view at E shows 9 welds. Figure 8 The wear-resistant belt shown is spiral and symmetrically arranged in the designated middle area of ​​the drill pipe body. Fig. 9 for Figure 8 In the enlarged view of point F, L1 represents the first preset distance, L2 represents the second preset distance, and L3 represents the designated middle area.

[0040] Embodiment 1 Combination Figures 1 to 9 As shown, the present application provides a drill pipe with a welded wear-resistant structure, comprising a drill pipe body 1, a designated middle area L3 of the drill pipe body 1 is provided with a wear-resistant structure, the wear-resistant structure comprises at least one wear-resistant belt 2, the wear-resistant belts 2 are arranged in sequence along the axial direction of the drill pipe body 1 around the outer surface of the drill pipe body 1, and each wear-resistant belt 2 is in a circular ring shape or a spiral shape; each wear-resistant belt 2 comprises a group of welds, and each weld in each group of welds is in a circular ring shape or a spiral shape. When the group of welds comprises multiple welds, the multiple welds are arranged adjacent to each other, and the multiple groups of welds are formed simultaneously by laser cladding welding.

[0041] In addition, each wear-resistant belt 2 includes a base layer structure and a surface layer structure; the base layer structure is connected to the outer surface of the drill pipe body 1, and the surface layer structure is connected to the corresponding base layer structure; the base layer structure includes at least one base layer, and at least one base layer is arranged on the outer surface in layers in a direction away from the outer surface; the surface layer structure includes at least one surface layer, and at least one surface layer is arranged on the base layer structure in layers in a direction away from the outer surface, and the width of the surface layer gradually decreases in the direction away from the outer surface; each base layer and surface layer are respectively formed by welding through a laser cladding process.

[0042] In combination with the above-mentioned embodiments, a drill pipe with a welded wear-resistant structure in this embodiment includes a drill pipe body 1, which can play a role in supporting and transmitting torque. The wear-resistant structure is arranged on a designated middle area L3 of the drill pipe body 1, and the designated middle area L3 is a part of the drill pipe body 1 that is easily worn during the drilling process, which can improve the wear resistance of the drill pipe body 1 during use, prevent the drill pipe body 1 from being worn through, and thus extend the service life of the drill pipe body 1. The wear-resistant structure includes at least one wear-resistant belt 2, which surrounds the outer surface of the drill pipe body 1 and is arranged in sequence along the axial direction of the drill pipe body 1, so that it can effectively cover the area of ​​the drill pipe body 1 that is most susceptible to wear, and can fully protect the drill pipe body 1 from wear during the drilling process.

[0043] Furthermore, the shape of the wear-resistant belt 2 can be selected according to the stress conditions of the drill pipe under different working conditions, for example, it can be annular or spiral. When the wear-resistant belt 2 is annular, it can provide circumferential wear protection for the drill pipe body 1, and when the drill pipe rotates, it can ensure that the degree of wear in all directions is relatively uniform. When the wear-resistant belt 2 is spiral, it can provide better wear protection when the drill pipe moves axially or simultaneously moves axially and rotationally, and due to its spiral structure, it can also guide the flow of materials such as drill cuttings to a certain extent, avoiding excessive accumulation on the surface of the drill pipe, thereby further reducing wear.

[0044] Further, each wear-resistant belt 2 includes a group of welds, and each weld in each group of welds is annular or spiral. When the group of welds includes multiple welds, multiple welds are arranged adjacent to each other, and the edges of every two adjacent welds overlap each other, which can reduce the probability of virtual welding, thereby improving the welding quality. Multiple groups of welds are formed by laser cladding process welding at the same time. Through the laser cladding process, a strong combination can be formed between the welds and the drill pipe body 1 and different welds. When the weld is annular, it can provide continuous wear protection for the drill pipe in the circumferential direction to prevent local wear on the surface of the drill pipe during the screwing process. When the weld is spiral, while ensuring wear resistance, the spiral structural characteristics can also be used to disperse the force when the drill pipe moves axially, avoiding local stress concentration, thereby improving the overall durability of the drill pipe. At the same time, multiple groups of welds are formed simultaneously, which can ensure the consistency and uniformity of the welding process and avoid structural deformation or stress concentration problems caused by multiple welding.

[0045] Furthermore, each wear-resistant belt 2 includes a base layer structure and a surface layer structure. The base layer structure is connected to the outer surface of the drill pipe body 1, and the base layer structure includes at least one base layer, and at least one base layer is arranged on the outer surface in layers in a direction away from the outer surface of the drill pipe body 1. The base layer structure can enhance the bonding strength between the wear-resistant belt 2 and the drill pipe body 1, and prevent the wear-resistant belt 2 from falling off the drill pipe body 1 during use. Since the base layers are arranged in layers in a direction away from the outer surface, each layer of the base layer can reinforce and enhance the bonding force of the next layer, thereby ensuring the stability of the entire wear-resistant structure. The surface layer structure is connected to the corresponding base layer, and the surface layer structure includes at least one surface layer, and at least one surface layer is arranged on the base layer structure in layers in a direction away from the outer surface, and the width of the surface layer gradually decreases in a direction away from the outer surface, which helps to optimize the force distribution of the wear-resistant structure. During the drilling process, the wear of the drill pipe surface often starts from the outermost layer. The design of gradually decreasing the width of the surface layer can make the wear-resistant material of the outer layer better withstand wear, and as wear occurs, the surface layer of the inner layer gradually plays a role, thereby extending the overall service life of the wear-resistant structure. At the same time, this structure also helps to disperse the external wear force to the surface layers at different levels, avoiding failure of the drill pipe due to excessive local wear. Moreover, each base layer and surface layer are welded by laser cladding process, which can accurately control the depth and width of welding, ensure the quality of each layer, and form a good connection between each layer and with the drill pipe body 1, thereby further enhancing the connection reliability between the wear-resistant structure and the drill pipe body 1, and avoiding the wear-resistant structure from falling off during drilling.

[0046] In a possible embodiment, the length range of the designated middle area L3 is positively correlated with the deflection of the drill pipe body 1 during operation, and the number of the wear-resistant belts 2 is positively correlated with the length of the designated middle area L3. The size of the designated middle area L3 is determined according to the overall length of the drill pipe. Generally speaking, the longer the length of the drill pipe body 1, the larger the range of the corresponding designated middle area L3. During the drilling process of the drill pipe, the drill pipe body 1, especially the middle part of the drill pipe body 1, will bend to a certain extent (i.e., the deflection of the drill pipe body 1) due to the centrifugal force. The longer drill pipe body 1 is more bent than the shorter drill pipe body 1. For example, when the length of the drill pipe body 1 is 10 meters, the range of the designated middle area L3 may be set within the area extending 1 meter to each end based on the midpoint of the drill pipe. If the length of the drill pipe increases to 20 meters, according to the proportional relationship and actual working conditions, the range of the designated middle area L3 may be expanded to about 0.5 meters to each end based on the midpoint. The size of the designated middle area L3 is also determined according to the rotation speed of the drill rod. Generally speaking, the greater the rotation speed of the drill rod, the larger the range of the corresponding designated middle area L3. During the drilling process, the greater the rotation speed of the drill rod, the greater the centrifugal force on the drill rod body 1, especially the middle part of the drill rod body 1. The bending degree of the drill rod body 1 with a higher rotation speed is greater than that of the drill rod body with a lower rotation speed. By determining the appropriate length of the designated middle area L3 according to the overall length and rotation speed of the drill rod, it is possible to meet the actual operation requirements, reduce the wear of the drill rod body 1 during the operation, and extend the service life of the drill rod body 1.

[0047] In a possible embodiment, the range of the designated middle area L3 in the drill pipe body 1 is 2 meters to 3 meters, and the number of the wear-resistant strips 2 is an even number and they are symmetrically arranged in the designated middle area L3 of the drill pipe body 1 .

[0048] In a possible embodiment, the wear-resistant structure includes a plurality of wear-resistant belts 2, and each wear-resistant belt 2 is in a circular ring shape, and a first preset spacing L1 is set between the plurality of wear-resistant belts 2. Theoretically, the smaller the first preset spacing L1, the better. When the first preset spacing L1 is infinitely close to zero, the plurality of wear-resistant structures form a whole, which can play the best wear-resistant role. However, in practice, the cost and construction period need to be considered. The size of the first preset spacing L1 needs to be designed according to the cost of the product and the time limit for completion, so that it can meet both the qualified wear resistance requirements and the cost and construction period requirements.

[0049] In a possible embodiment, the first preset maximum distance The first preset spacing L1 is selected from a range of maximum values ​​according to the dogleg degree of the drill pipe during drilling and the weld thickness of the wear-resistant belt 2. The maximum value of the first preset spacing is With the following relationship: ; in, Represents the maximum value of the first preset spacing L1 of multiple wear-resistant belts 2; R represents the radius of curvature corresponding to the dogleg degree; t represents the weld thickness of the wear-resistant belt 2, and the weld thickness of multiple wear-resistant belts 2 is the same. The wellbore is not always straight downward during the drilling process, and it often bends due to geological conditions, drilling technology and other factors. The dogleg degree is a quantitative representation of this degree of curvature. The unit of dogleg degree is usually degree / 30 meters, which refers to the spatial change angle of the wellbore direction within the 30-meter well section length. For example, if the direction of the wellbore changes by 5 degrees in a 30-meter well section, then the dogleg degree here is 5 degrees / 30 meters. It can be seen from the above relationship that when the weld thickness of the wear-resistant belt 2 is a constant and the greater the dogleg degree, the smaller the first preset spacing L1. This is because the greater the dogleg degree, the more severe the wellbore curvature. In order to ensure that the wear-resistant belt 2 can effectively adapt to the wellbore curvature and provide good wear-resistant protection, the first preset spacing L1 needs to be reduced accordingly to ensure that at the wellbore curvature, the wear-resistant belt 2 can still evenly disperse the friction and other forces acting on the drill pipe body 1, reduce the wear risk of the drill pipe body 1, and ensure the safety and stability of the drilling operation.

[0050] In a possible embodiment, the wear-resistant structure includes a plurality of wear-resistant belts 2, and each wear-resistant belt 2 is spiral; each wear-resistant belt 2 is arranged with equal pitch and the pitch of the plurality of wear-resistant belts 2 is the same, and the pitch is determined by the direction of the tensile stress and the dogleg degree of the drill pipe during drilling. From the perspective of the direction of the tensile stress on the drill pipe body 1, when the drill pipe is operating underground, different working conditions will cause the drill pipe body 1 to be subjected to tensile stresses of different directions and magnitudes. For example, during vertical drilling, the tensile stress is mainly distributed along the axial direction of the drill pipe body 1. During directional drilling, the direction of the tensile stress will change with the change of the wellbore trajectory. The change in the direction of the tensile stress will affect the force condition of the wear-resistant belt 2, and then affect the setting of the pitch. If the direction of the tensile stress is relatively stable, the pitch of the wear-resistant belt 2 can be relatively large; if the direction of the tensile stress changes frequently, in order to ensure that the wear-resistant belt 2 can effectively disperse the stress, the pitch needs to be appropriately reduced.

[0051] In a possible embodiment, multiple wear-resistant belts 2 are separated by a second preset spacing L2. Theoretically, the smaller the second preset spacing L2 is, the better. When the second preset spacing L2 is infinitely close to zero, multiple wear-resistant structures form a whole, which can play the best wear-resistant role. However, in fact, the cost and construction period must also be considered. The size of the second preset spacing L2 needs to be designed according to the cost of the product and the completion time limit, so that it can meet the qualified wear resistance requirements and meet the cost and construction period requirements.

[0052] In a possible embodiment, the maximum value of the second preset interval The second preset spacing L2 is selected from the range of the maximum value according to the dogleg degree of the drill pipe during drilling and the weld thickness of the wear-resistant belt 2. The maximum value of the second preset spacing is With the following relationship: ; in, represents the maximum value of the second preset spacing L2 between multiple wear-resistant belts 2; R represents the radius of curvature corresponding to the dogleg degree; t represents the weld thickness of the wear-resistant belt 2, and the thickness of multiple wear-resistant belts 2 is the same. It can be seen from the above relationship that when the weld thickness of the wear-resistant belt 2 is a constant value and the greater the dogleg degree, the smaller the second preset spacing L2. This is because the greater the dogleg degree, the more severe the wellbore curvature. In order to ensure that the wear-resistant belt 2 can effectively adapt to the wellbore curvature and provide good wear protection, the second preset spacing L2 needs to be reduced accordingly to ensure that at the wellbore curvature, the wear-resistant belt 2 can still evenly disperse the friction and other forces on the drill pipe body 1, reduce the wear risk of the drill pipe body 1, and ensure the safety and stability of the drilling operation.

[0053] In a possible embodiment, the thickness range and width range of the wear-resistant strip 2 are determined in the following manner: According to the drill pipe's own strength, its own wear resistance and the force information of the drill pipe during drilling, the overall strength and overall wear resistance of the drill pipe with welded wear-resistant belt 2 are determined; the overall strength is not less than the drill pipe's own strength and the overall wear resistance is greater than the own wear resistance; Taking the overall strength and overall wear resistance as constraint conditions, the thickness range and width range of the wear-resistant belt 2 are determined in combination with the material and welding process of the wear-resistant belt 2 .

[0054] In combination with the above embodiments, different materials of the wear-resistant belt 2 have different properties such as hardness, wear resistance, and bonding strength with the drill rod. For example, cemented carbide material is selected as the wear-resistant belt 2, which has high hardness and good wear resistance, but it is difficult to weld with the drill rod. The welding process is relatively simple when ordinary alloy materials are used, but the wear resistance may be poor. At the same time, the welding process will also affect the bonding quality of the wear-resistant belt 2 and the drill rod and the final overall performance. If the welding process is improper, problems such as cold welding and desoldering may occur, thereby affecting the use effect of the wear-resistant belt 2. By selecting different combinations of wear-resistant belt 2 materials, welding processes, thicknesses, and widths, it is determined that the reasonable thickness range and width range of the wear-resistant belt 2 meet the requirements of overall strength and overall wear resistance, so that the drill rod welded with the wear-resistant belt 2 can achieve ideal overall strength and overall wear resistance.

[0055] In a possible embodiment, each weld bead in a group of weld bead included in each hard-wearing belt 2 has the same thickness; the target thickness and target width of the weld bead are determined by the following method: The number of layers and the thickness of each layer of the wear-resistant belt 2 are determined according to the thickness range of the weld, the heat input of the welding tool and the welding process. The first number of layers of each base layer, the first thickness of each layer, and the second number of layers of each surface layer and the second thickness of each surface layer are determined by the laser cladding process. The target thickness of the weld is determined according to the first number of layers, the first thickness, the second number of layers and the second thickness. For example, by controlling the heat input of the welding tool and combining different welding process parameters, it is determined that the first number of layers of the base layer is 3 layers, the first thickness of each layer is 1 mm, the second number of layers of the surface layer is 2 layers, and the second thickness of each layer is 1.5 mm. The target thickness of the weld is thus calculated and determined, and the target thickness is the sum of the total thickness of the base layer and the total thickness of the surface layer, that is, the target thickness is 6 mm.

[0056] The target width of each layer of the wear-resistant belt 2 is determined according to the width range of the weld, the type of welding tool spot and the welding process. Different types of welding tool spots, such as circular spots and rectangular spots, have different effects on the width of the weld. For example, when using a circular spot for welding, the minimum width of the wear-resistant belt 2 is 19 mm, and the target width needs to be greater than or equal to this minimum width to ensure that the wear-resistant belt 2 can meet the actual wear resistance and force requirements.

[0057] In some embodiments, the thickness of the wear-resistant belt 2 ranges from 4.0 mm to 6.0 mm, and the width of the wear-resistant belt 2 ranges from 19 mm to 30 mm, which can better adapt to the complex working conditions of the drill pipe during the drilling process.

[0058] In some embodiments, the wear-resistant structure corresponds to a wear factor, and the wear factor is determined according to the application object of the drill pipe and the user's demand for the application object. Correspondingly, the wear factor of the wear-resistant structure is calculated by one or more wear-resistant belts 2 included therein. Among them, the wear factor includes a reference wear factor and a differential wear factor; the reference wear factor is calculated according to the contact pressure of the drill pipe when drilling under specified conditions in a simulated scenario; the differential wear factor is calculated according to the contact pressure of the drill pipe when drilling when the wear-resistant structure changes at least one parameter (contact pressure and material hardness) in the specified conditions in a simulated scenario; the contact pressure is obtained by measuring the drill pipe in the target area in a simulated scenario; the contact pressure corresponding to different time periods and / or different target areas is different.

[0059] The above parameters include contact pressure and material hardness. By comprehensively referring to the wear factor and various differential wear factors, we can fully understand the changes in the wear performance of the wear-resistant structure under different parameters, so that we can choose drill pipes with suitable wear performance according to different use environments. For example, an increase in contact pressure will increase the wear factor, and a higher contact pressure will aggravate the wear of the drill pipe. The increase in material hardness will reduce the wear factor, and the use of materials with higher hardness in the wear-resistant structure can reduce the wear of the drill pipe.

[0060] In a possible embodiment, the outer surface of the drill pipe body 1 is a circumferential surface, and when each wear-resistant belt 2 is spiral, the wear-resistant belt 2 surrounds at least one circumference of the outer surface of the drill pipe body 1. During the drilling process, when the drill pipe rotates, the spiral wear-resistant belt 2 can continuously and evenly disperse the friction and wear force from the surrounding medium, thereby avoiding local excessive wear.

[0061] In a possible embodiment, the base layer structure and the surface layer structure are formed by welding through a laser cladding process, including: Determine the welding materials, welding methods and welding parameters of the base layer structure and the surface layer structure respectively; Determine the welding path of the welding tool according to the preset shape of each wear-resistant belt 2, and control the welding tool to weld in sequence along the welding path to form a base layer and a surface layer in sequence; The base layer formed by welding has at least one layer and surrounds at least one circumference of the outer surface, the surface layer formed by welding has at least one layer and surrounds at least one circumference of the outer surface, and the width of the surface layer decreases in the direction away from the outer surface.

[0062] The wear-resistant belt 2 composed of the base layer structure and the surface layer structure prepared by the above-mentioned laser cladding process is firmly combined with the drill pipe matrix due to the reasonable selection of the base layer and the surface layer materials, the optimization of welding parameters and the precise control of the welding path. The special structural design of the surface layer further improves its wear resistance, improves the wear resistance of the drill pipe, helps to reduce drilling costs and improve operating efficiency.

[0063] In a possible embodiment, the welding parameters are determined by the following method, including: The welding parameters are determined according to the thickness and heat input of the hard-resistant belt 2. Hard-resistant belts 2 of different thicknesses require different welding strengths and penetration depths to ensure welding quality and the performance of the hard-resistant belt 2. By determining the parameters according to the thickness, the welding parameters can be accurately determined to avoid problems such as insufficient welding (such as weak bonding) or excessive welding (such as burn-through, excessive deformation) caused by improper parameters. At the same time, the welding parameters are also determined according to the heat input, which helps to accurately control the heat-affected zone during the welding process, avoid the increase of the heat-affected zone due to excessive heat input, and then reduce the structural performance of the drill pipe body 1.

[0064] The welding parameters include welding power, linear speed and powder feeding amount; the welding power includes base layer power and surface layer power, wherein the base layer power is pre-adjusted to match each base layer power, and the surface layer power is adjusted based on the base layer power. The adjustment includes increasing or decreasing the base layer power within the set range, and the setting range is less than 1kw. The linear speed of the drill pipe body 1 is 15~30mm / s, and the powder feeding amount to the drill pipe body 1 is 1.5~2.5g / s. The base layer is directly welded to the drill pipe body 1, and the welding quality of the base layer affects the stability of the entire wear-resistant belt 2. The accurately set base layer power can ensure a good combination of the base layer and the drill pipe body 1, avoid defects such as unfusion and slag inclusion, and facilitate the subsequent surface layer welding process. In addition, the surface layer power is increased or decreased based on the base layer power within a set range of less than 1kW. This adjustment method not only ensures the correlation with the base layer welding parameters, but also can be flexibly optimized according to actual conditions (such as surface quality requirements, material properties of the wear-resistant belt 2, etc.). The smaller adjustment range ensures the stability of the welding process and will not cause welding defects due to excessive power changes. At the same time, the surface layer welding effect can be finely adjusted to meet different usage requirements, thereby improving the overall welding quality of the wear-resistant belt 2.

[0065] The linear speed of the rotation of the drill rod body 1 is 15-30 mm / s, which can ensure the stability and continuity of the welding process, and is conducive to uniform welding along the outer circumference of the drill rod body 1, avoiding problems such as shallow weld depth and discontinuity due to too fast speed, or overheating of the weld and coarse grains due to too slow speed, thereby ensuring the welding quality of the wear-resistant belt 2. In addition, the powder feeding amount of the drill rod body 1 is controlled within the range of 1.5-2.5 g / s, which can ensure the stable supply of welding powder during the welding process, and the appropriate powder feeding amount is matched with the welding power and linear speed, thereby improving the welding quality of the wear-resistant belt 2. In a possible embodiment, the power of the base layer is greater than or equal to 2.0KW. The number of layers of the base layer is at least one, and the thickness of each layer of the base layer is 0.8mm-1.2mm; the number of layers of the surface layer is multiple; the surface temperature of the wear-resistant belt 2 formed by welding does not exceed 200°C, and the melting depth of the outer surface does not exceed 2mm.

[0066] In a possible embodiment, the base layer of the wear-resistant structure corresponds to a Rockwell hardness, and the Rockwell hardness is correlated with the wear factor of the wear-resistant structure. The Rockwell hardness is a parameter reflecting the hardness of the wear-resistant belt 2 material, and the wear factor is a parameter reflecting the wear characteristics of the wear-resistant belt 2 material. Through the relatively easy-to-measure Rockwell hardness, the wear condition of the wear-resistant structure in actual use can be indirectly understood, so that the wear resistance performance can be more clearly predicted in the design and manufacturing stages.

[0067] Among them, the correlation between Rockwell hardness and the wear factor of the wear-resistant structure is determined in the following manner: according to the application scenario and application object of the drill pipe, the correlation between the Rockwell hardness and the wear factor of the wear-resistant structure in the wear-resistant belt 2 is determined; the correlation includes multiple combinations of multiple preset Rockwell hardness ranges and multiple preset wear factor ranges, and the number of combinations is equal to the product of the number of preset Rockwell hardness ranges and the number of preset wear factor ranges. Different scenarios and application objects have different selected correlations. Multiple combinations are made between multiple preset Rockwell hardness ranges and multiple preset wear factor ranges. Different scenarios and application objects can select a more suitable group from many combinations, so as to achieve better wear resistance of the wear-resistant belt 2 and adapt to diverse actual needs. The number of combinations is equal to the product of the number of preset Rockwell hardness ranges and the number of preset wear factor ranges, which provides a rich selection space for complex and changeable drill pipe use environments. Even in the face of some extreme or rare working conditions, it is possible to find a suitable wear-resistant structure through these combinations to improve the reliability and stability of the drill pipe under various complex conditions.

[0068] In a possible embodiment, the Rockwell hardness of the wear-resistant strip 2 is 40HRC-60HRC.

[0069] In a possible embodiment, the welding spot of the welding tool is a rectangular spot or a circular spot.

[0070] Embodiment 2 The present application also provides a method for welding a wear-resistant structure in a drill pipe, comprising the following steps: Step 1: Determine the first structural parameters of the wear-resistant structure and the second structural parameters of a single wear-resistant belt 2. The first structural parameters include the shape, quantity and preset spacing of the wear-resistant belt. The preset spacing selects the first preset spacing L1 or the second preset spacing L2 according to the shape of the wear-resistant belt 2. The second structural parameter includes the weld thickness. The preset spacing in the first structural parameter selects the first preset spacing L1 or the second preset spacing L2 according to the shape of the wear-resistant belt 2, so that the layout of the wear-resistant belt 2 can be optimized according to different shape characteristics. In actual applications, the stress conditions and wear-resistant effects of wear-resistant belts 2 of different shapes are different. By selecting a suitable preset spacing, the wear-resistant belt 2 can be reasonably distributed on the surface of the drill pipe, thereby improving the overall wear resistance of the drill pipe. In addition, the appropriate weld thickness can ensure the connection strength between the wear-resistant belt 2 and the drill pipe, prevent the wear-resistant belt 2 from falling off during use, and also ensure the strength and wear resistance of the wear-resistant belt 2 itself, thereby improving the service life of the drill pipe.

[0071] Step 2: According to the first structural parameter and the second structural parameter, determine the target welding tool and target welding method for the wear-resistant structure in the drill pipe. Different welding methods are suitable for different materials and welding requirements. Selecting a suitable welding method can ensure good welding between the wear-resistant belt 2 and the drill pipe body 1. At the same time, determining reasonable welding tools and target welding methods, such as using a laser welding gun and laser cladding welding method, and controlling the welding current, voltage, welding speed, etc. of the welding gun can further optimize the welding process, reduce the occurrence of welding defects, and thus improve the welding quality.

[0072] Step 3: Determine welding process parameters according to the first structural parameter, the second structural parameter and the multi-dimensional parameter information of the drill pipe, the multi-dimensional parameter information including: material information, structural information and welding performance. Determine the welding process parameters according to the first structural parameter and the second structural parameter determined above, so as to ensure that the welding setting of the wear-resistant belt 2 on the surface of the drill pipe meets the design requirements, avoid the situation of local excessive wear, and thus improve the overall wear resistance and service life of the drill pipe.

[0073] Step 4: Control the target welding tool to use the target welding method and weld the wear-resistant belt according to the welding process parameters to obtain the wear-resistant structure in the drill pipe, thereby improving the welding quality of the wear-resistant structure.

[0074] In some embodiments, when the wear-resistant structure includes a plurality of wear-resistant belts 2 and each wear-resistant belt 2 is in a circular ring shape, the plurality of wear-resistant belts 2 are set at a first preset spacing L1, and the second structural parameter includes a weld thickness; the first structural parameter of the wear-resistant structure and the second structural parameter of a single wear-resistant belt 2 are determined, and the weld thickness of the plurality of wear-resistant belts is the same. Wherein, determining the first preset spacing and the weld thickness includes: According to the maximum value of the first preset distance The relationship between the two is determined by the relationship between the two parameters, and the matching weld thickness is selected from the series parameter values ​​according to the construction environment. Then, the matching first preset spacing L1 is calculated according to the formula. The relationship is as follows: ; in, represents the maximum value of the first preset spacing of the multiple wear-resistant belts 2; R represents the curvature radius corresponding to the dog-leg degree; t represents the weld thickness of the wear-resistant belt 2, and the weld thickness of the multiple wear-resistant belts 2 is the same. The size of the first preset spacing L1 is designed according to the cost of the product and the time limit for completion, so that it can meet the qualified wear resistance requirements and also meet the requirements of cost and construction period.

[0075] In some embodiments, when the wear-resistant structure includes a plurality of wear-resistant belts 2 and each wear-resistant belt 2 is spiral, the plurality of wear-resistant belts 2 are spaced apart by a second preset spacing L2, and the second structural parameter includes the weld thickness; determining the first structural parameter of the wear-resistant structure and the second structural parameter of a single wear-resistant belt 2 includes: According to the drill pipe's own strength, its own wear resistance and the force information of the drill pipe during drilling, the overall strength and overall wear resistance of the welded wear-resistant belt drill pipe are determined; the overall strength is not less than the drill pipe's own strength and the overall wear resistance is greater than the own wear resistance; Taking the overall strength and overall wear resistance as constraints, the thickness range of the wear-resistant belt is determined in combination with the material and welding process of the wear-resistant belt, and the weld thickness of the wear-resistant belt is determined from the thickness range; According to the construction environment, a suitable weld thickness is selected from the series of values, and then the maximum value of the first preset spacing is calculated according to the dogleg degree of the drill pipe during drilling and the selected weld thickness, and the first preset spacing is selected from the maximum value: ; Wherein, L represents the maximum value of the first preset spacing of the plurality of wear-resistant belts; R represents the radius of curvature corresponding to the dog-leg degree; and t represents the weld thickness of the wear-resistant belt.

[0076] The size of the second preset spacing L2 is designed according to the cost of the product and the time limit for completion, so that it can meet the qualified wear resistance requirements and also meet the requirements of cost and construction period.

[0077] In some embodiments, the second structural parameter also includes a pitch, and each wear-resistant belt 2 is set with the same pitch; determining the second structural parameter of a single wear-resistant belt 2 of the wear-resistant structure also includes: determining the pitch by the direction and dogleg degree of the tensile stress borne by the drill pipe during drilling. From the perspective of the direction of the tensile stress borne by the drill pipe body 1, when the drill pipe is operating underground, different working conditions will cause the drill pipe body 1 to be subjected to tensile stresses of different directions and magnitudes. For example, during vertical drilling, the tensile stress is mainly distributed along the axial direction of the drill pipe body 1. During directional drilling, the direction of tensile stress will change with the change of the wellbore trajectory. Changes in the direction of tensile stress will affect the force conditions of the wear-resistant belt 2, and then affect the setting of the pitch. If the direction of tensile stress is relatively stable, the pitch of the wear-resistant belt 2 can be relatively large; if the direction of tensile stress changes frequently, in order to ensure that the wear-resistant belt 2 can effectively disperse the stress, the pitch needs to be appropriately reduced.

[0078] In some embodiments, the second structural parameter also includes the thickness and width of the wear-resistant belt 2; determining the first structural parameter of the wear-resistant structure and the second structural parameter of a single wear-resistant belt 2 also includes: determining the overall strength and overall wear resistance of the drill pipe welded with the wear-resistant belt 2 according to the strength of the drill pipe itself and the force information of the drill pipe during drilling. Taking the overall strength and overall wear resistance as constraints, the thickness range and width range of the wear-resistant belt 2 are determined in combination with the material and welding process of the wear-resistant belt 2. Different materials of the wear-resistant belt 2 have different properties such as hardness, wear resistance, and bonding strength with the drill pipe. For example, the use of cemented carbide material as the wear-resistant belt 2 has high hardness and good wear resistance, but it is difficult to weld with the drill pipe, while the use of ordinary alloy material has a relatively simple welding process, but the wear resistance may be poor. At the same time, the welding process will also affect the bonding quality of the wear-resistant belt 2 and the drill pipe and the final overall performance. If the welding process is improper, problems such as cold welding and desoldering may occur, thereby affecting the use effect of the wear-resistant belt 2. By selecting different combinations of wear-resistant belt 2 materials, welding processes, thicknesses and widths, the reasonable thickness range and width range of the wear-resistant belt 2 can be determined while meeting the overall strength and overall wear resistance requirements, so that the drill pipe welded with the wear-resistant belt 2 can achieve ideal overall strength and overall wear resistance.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A drill pipe with a welded wear-resistant structure, characterized in that: The invention comprises a drill pipe body, wherein a wear-resistant structure is arranged in a designated middle area of ​​the drill pipe body, wherein the wear-resistant structure comprises at least one wear-resistant belt, wherein the wear-resistant belt is sequentially arranged around the outer surface of the drill pipe body along the axial direction of the drill pipe body, and each of the wear-resistant belts is in a circular ring shape or a spiral shape; each of the wear-resistant belts comprises a group of weld beads, and each weld bead in each group of weld beads is in a circular ring shape or a spiral shape. When the group of weld beads comprises a plurality of weld beads, the plurality of weld beads are arranged adjacent to each other, and the plurality of groups of weld beads are welded and formed simultaneously by a laser cladding process; Each wear-resistant belt includes a base layer structure and a surface layer structure; the base layer structure is connected to the outer surface of the drill pipe body, and the surface layer structure is connected to the corresponding base layer structure; the base layer structure includes at least one base layer, and at least one base layer is arranged on the outer surface in a layered manner away from the outer surface; the surface layer structure includes at least one surface layer, and at least one surface layer is arranged on the base layer structure in a layered manner away from the outer surface, and the width of the surface layer gradually decreases in a direction away from the outer surface; each of the base layer and the surface layer are respectively formed by welding through a laser cladding process.

2. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: The wear-resistant structure includes a plurality of wear-resistant belts, and each of the wear-resistant belts is in a circular ring shape, and the plurality of wear-resistant belts are arranged at a first preset spacing; the maximum value of the first preset spacing is determined according to the dogleg degree of the drill pipe during drilling and the weld thickness of the wear-resistant belt, and the first preset spacing is selected from the maximum value: ； in, It represents the maximum value of the first preset spacing of multiple wear-resistant belts; R represents the curvature radius corresponding to the dog-leg degree; t represents the weld thickness of the wear-resistant belt, and the weld thickness of the multiple wear-resistant belts is the same.

3. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: The wear-resistant structure includes a plurality of wear-resistant belts, and each of the wear-resistant belts is spiral; each of the wear-resistant belts is arranged with equal pitch and the pitch of the plurality of wear-resistant belts is the same, and the pitch is determined by the direction of the tensile stress and the dogleg degree of the drill pipe during drilling; the plurality of wear-resistant belts are spaced apart by a second preset spacing; and the second preset spacing is determined according to the dogleg degree of the drill pipe during drilling: ； in, represents the maximum value of the second preset spacing between multiple wear-resistant belts; R represents the curvature radius corresponding to the dog-leg degree; t represents the weld thickness of the wear-resistant belt, and the thickness of the multiple wear-resistant belts is the same.

4. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: The thickness range and width range of the wear-resistant belt are determined as follows: Determine the overall strength and overall wear resistance of the drill pipe with a welded wear-resistant belt according to the drill pipe's own strength, its own wear resistance and the force information of the drill pipe during drilling; the overall strength is not less than the drill pipe's own strength and the overall wear resistance is greater than the own wear resistance; Taking the overall strength and overall wear resistance as constraint conditions, the thickness range and width range of the wear-resistant belt are determined in combination with the material and welding process of the wear-resistant belt.

5. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: Each of the welds in a group of welds included in each hard-wearing belt has the same thickness; the target thickness and target width of the weld are determined by the following method: Determine the number of layers of the wear-resistant belt and the thickness of each layer according to the thickness range of the weld, the heat input of the welding tool and the welding process, determine the first number of layers of each base layer, the first thickness of each layer, and the second number of layers of each surface layer and the second thickness of each surface layer by laser cladding process, and determine the target thickness of the weld according to the first number of layers, the first thickness, the second number of layers and the second thickness; The target width of each layer of the wear-resistant belt is determined according to the width range of the weld bead, the type of welding tool spot and the welding process.

6. The drill pipe with a welded wear-resistant structure according to claim 4, characterized in that: The thickness of the wear-resistant belt ranges from 4.0 mm to 6.0 mm, and the width of the wear-resistant belt ranges from 19 mm to 30 mm.

7. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: The wear-resistant structure corresponds to a wear factor, and the wear factor is determined according to the application object of the drill pipe and the user's demand for the application object; correspondingly, the wear factor of the wear-resistant structure is calculated through one or more wear-resistant belts included therein; Among them, the wear factor includes a reference wear factor and a differential wear factor; the reference wear factor is calculated based on the contact pressure of the drill pipe when drilling under specified conditions in a simulation scenario; the differential wear factor is calculated based on the contact pressure of the drill pipe when drilling when the wear-resistant structure changes at least one parameter in the specified conditions in the simulation scenario; the contact pressure is obtained by measuring the drill pipe in the target area in the simulation scenario; different time periods and / or different target areas correspond to different contact pressures.

8. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: The length range of the designated middle area has a positive correlation with the deflection of the drill pipe body during operation, and the number of the wear-resistant belts has a positive correlation with the length of the designated middle area.

9. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: The overall length range of the designated middle area is 2m-3m, and the number of the wear-resistant belts is an even number and they are symmetrically arranged in the designated middle area of ​​the drill pipe body.

10. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: The outer surface of the drill pipe body is a circumferential surface. When each of the wear-resistant belts is in a spiral shape, the wear-resistant belt surrounds at least one circumference of the outer surface of the drill pipe body.

11. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: The base layer structure and the surface layer structure are formed by welding through a laser cladding process, including: Determining welding materials, welding methods and welding parameters of welding tools for the base layer structure and the surface layer structure respectively; Determine a welding path of the welding tool according to the preset shape of each of the wear-resistant belts, and control the welding tool to weld in sequence along the welding path to successively form the base layer and the surface layer; The base layer formed by welding has at least one layer and surrounds at least one circumference of the outer surface, the surface layer formed by welding has at least one layer and surrounds at least one circumference of the outer surface, and the width of the surface layer decreases in the direction away from the outer surface.

12. The drill pipe with a welded wear-resistant structure according to claim 11, characterized in that: The welding parameters are determined by: The welding parameters are determined according to the thickness and heat input of the wear-resistant belt, and the welding parameters include welding power, line speed and powder feeding amount; the welding power includes base layer power and surface layer power, wherein the base layer power is pre-adjusted to match the power of each base layer, and the surface layer power is adjusted based on the power of the base layer, and the adjustment includes increasing or decreasing the base layer power within a set range, and the set range is less than 1kw; the line speed is 15~30mm / s, and the powder feeding amount is 1.5~2.5g / s.

13. The drill pipe with a welded wear-resistant structure according to claim 12, characterized in that: The base layer power is greater than or equal to 2.0KW.

14. The drill pipe with a welded wear-resistant structure according to claim 1, characterized in that: The number of layers of the base layer is at least one, and the thickness of each layer of the base layer is 0.8mm~1.2mm; the number of layers of the surface layer is multiple; the surface temperature of the wear-resistant belt monomer formed by welding does not exceed 200°C; the melting depth of the outer surface does not exceed 2mm.

15. The drill pipe with a welded wear-resistant structure according to claim 7, characterized in that: The wear-resistant structure base layer corresponds to a Rockwell hardness, and the Rockwell hardness is correlated with the wear factor of the wear-resistant structure; Among them, the correlation is determined in the following manner: according to the application scenario and application object of the drill pipe, the correlation between the Rockwell hardness and the wear factor of the wear-resistant structure in the wear-resistant belt is determined; the correlation includes multiple combinations of multiple preset Rockwell hardness ranges and multiple preset wear factor ranges, and the number of combinations is equal to the product of the number of preset Rockwell hardness ranges and the number of preset wear factor ranges.

16. The drill pipe with a welded wear-resistant structure according to claim 15, characterized in that: The Rockwell hardness of the wear-resistant belt is 40HRC-60HRC.

17. The drill pipe with a welded wear-resistant structure according to claim 11, characterized in that: The welding spot of the welding tool is a rectangular spot or a circular spot.

18. A method for welding a wear-resistant structure in a drill pipe, characterized in that: include: Determining a first structural parameter of a wear-resistant structure in a drill pipe and a second structural parameter of a single wear-resistant belt in the wear-resistant structure; Determining a target welding tool and a target welding method for the wear-resistant structure in the drill pipe according to the first structural parameter and the second structural parameter; Determine welding process parameters according to the first structural parameter, the second structural parameter and the multi-dimensional parameter information of the drill rod; wherein the multi-dimensional parameter information includes: material information, structural information and welding performance; The target welding tool is controlled to use the target welding method and weld the wear-resistant belt according to the welding process parameters to obtain a wear-resistant structure in the drill pipe.

19. The welding method of the wear-resistant structure in the drill pipe according to claim 18, characterized in that: When the wear-resistant structure includes a plurality of wear-resistant belts and each of the wear-resistant belts is in a circular ring shape, the first structural parameter includes a first preset spacing, and the first preset spacing is set between the plurality of wear-resistant belts; the second structural parameter includes a weld thickness, and the weld thicknesses of the plurality of wear-resistant belts are the same; Wherein, determining the first preset spacing and the weld thickness includes: Determine the overall strength and overall wear resistance of the drill pipe with a welded wear-resistant belt according to the drill pipe's own strength, its own wear resistance and the force information of the drill pipe during drilling; the overall strength is not less than the drill pipe's own strength and the overall wear resistance is greater than the own wear resistance; Taking the overall strength and overall wear resistance as constraints, determining the thickness range of the wear-resistant belt in combination with the material and welding process of the wear-resistant belt, and determining the weld thickness of the wear-resistant belt from the thickness range; The maximum value of the first preset spacing is determined according to the dogleg degree of the drill pipe during drilling and the weld thickness of the wear-resistant belt, and the first preset spacing is selected from the maximum value: ； in, represents the maximum value of the first preset spacing of multiple wear-resistant belts; R represents the curvature radius corresponding to the dog-leg degree; t represents the weld thickness of the wear-resistant belt.

20. The welding method of the wear-resistant structure in the drill pipe according to claim 18, characterized in that: When the wear-resistant structure includes a plurality of wear-resistant belts and each of the wear-resistant belts is spiral, the first structural parameter includes a second preset spacing, and the plurality of wear-resistant belts are spaced apart by the second preset spacing; The second structural parameter includes weld thickness, and the weld thicknesses of the plurality of wear-resistant belts are the same; Determining the second preset spacing and the weld thickness includes: Determine the overall strength and overall wear resistance of the drill pipe with a welded wear-resistant belt according to the drill pipe's own strength, its own wear resistance and the force information of the drill pipe during drilling; the overall strength is not less than the drill pipe's own strength and the overall wear resistance is greater than the own wear resistance; Taking the overall strength and overall wear resistance as constraints, determining the thickness range of the wear-resistant belt in combination with the material and welding process of the wear-resistant belt, and determining the weld thickness of the wear-resistant belt from the thickness range; The maximum value of the first preset spacing is determined according to the dogleg degree of the drill pipe during drilling and the weld thickness of the wear-resistant belt, and the second preset spacing is selected from the maximum value: ； in, represents the maximum value of the second preset spacing between multiple wear-resistant belts; R represents the curvature radius corresponding to the dog-leg degree; t represents the weld thickness of the wear-resistant belt, and the thickness of the multiple wear-resistant belts is the same.

21. The method for welding a wear-resistant structure in a drill pipe according to claim 18, characterized in that: The second structural parameter also includes a pitch, and each of the wear-resistant belts is set with the same pitch; the second structural parameter of a single wear-resistant belt in the wear-resistant structure is determined, and further includes: The pitch is determined by the direction of the tensile stress borne by the drill pipe during the drilling process and the dog-leg degree.

22. The welding method of the wear-resistant structure in the drill pipe according to claim 18, characterized in that: The second structural parameter also includes the width of the wear-resistant belt; the second structural parameter of a single wear-resistant belt in the wear-resistant structure is determined, and further includes: Determine the overall strength and overall wear resistance of the welded wear-resistant belt drill pipe according to the inherent strength of the drill pipe and the force information of the drill pipe during the drilling process; The overall strength and overall wear resistance are used as constraint conditions, and the width range of the wear-resistant belt is determined in combination with the material and welding process of the wear-resistant belt.

Images